2014 Expedition Misfired twice

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Thunderbirdsport

Full Access Members
Joined
Dec 10, 2020
Posts
377
Reaction score
233
Location
Missouri
Yes, the new plugs in mine solved the issue. Never a doubt they wouldn't. The gaps on the old plugs were quite large. Bet the mileage goes up a little, we'll see. Gonna be a nice road trip saturday, weather permitting.
 

Machete

My Rig. 2000 EB 4x4 5.4L
Joined
Jul 18, 2012
Posts
843
Reaction score
348
Location
Illinois
I change everything. COPs, boots, plugs.

I like preventing problems vs waiting for something to fail.

I am now driving 500-1000 miles week. Just got home today and since yesterday till now I clocked 650. I’ve gone through 3 1/2 tank fills this week.

My truck never had a misfire.

Now I’m thinking of replacing the alternator it has over 100k miles.
 

07navi

Full Access Members
Joined
Feb 3, 2020
Posts
2,538
Reaction score
592
Location
Mt.Shasta California
I change everything. COPs, boots, plugs.

I like preventing problems vs waiting for something to fail.

I am now driving 500-1000 miles week. Just got home today and since yesterday till now I clocked 650. I’ve gone through 3 1/2 tank fills this week.

My truck never had a misfire.

Now I’m thinking of replacing the alternator it has over 100k miles.
"if it ain't broke don't fix it". The alternator on my last truck was still good when I sold it at over 200k miles. Also you can sometimes do more harm than good by changing things.
 

ManUpOrShutUp

Full Access Members
Joined
Mar 27, 2016
Posts
2,038
Reaction score
1,076
Location
PA
You can't get more than 45K on plugs despite what Ford claims. It is a myth.

I've seen quite a bit of anecdotal evidence that the 3.5 eats plugs, but I've never seen any claims regarding that on the 5.4. My original plugs got changed at 95K and the second set around 180K. Motorcraft platinum plugs both times. No indication in either case that the plugs were overdue. 45K on the 5.4 seems like throwing money away unless you're using some seriously ****** plugs.


I change everything. COPs, boots, plugs.

I like preventing problems vs waiting for something to fail.

I am now driving 500-1000 miles week. Just got home today and since yesterday till now I clocked 650. I’ve gone through 3 1/2 tank fills this week.

My truck never had a misfire.

Now I’m thinking of replacing the alternator it has over 100k miles.

It's your money to spend however you please, but the COPs and boots are either good or they're not. I know replacing the COPs like they're a maintenance item is a thing for the Expedition crowd, but they virtually never fail if plugs are replaced in a timely fashion. And the boots, well it's easy enough to inspect them now and then just like you would any other rubber hose, etc. If they're starting to look suspect, by all means replace them, but doing it when they're still in great shape doesn't achieve anything.

And the alternator at 100K? Just like that? Why not test it? And why at 100K? I have literally never had an alternator fail before 200K, but if I was going to replace it "just because" as part of some sort of bizarre maintenance routine, 100K seems way, way too early nonetheless.
 

07navi

Full Access Members
Joined
Feb 3, 2020
Posts
2,538
Reaction score
592
Location
Mt.Shasta California
This time I almost totally agree. I must say though; all plugs start wearing from day one and the loss of mpg's and hp is so gradual that nobody notices it. Also; the sp515 plugs were the first upgrade from the ones that broke in the earlier models, cost much less, and work fine. Also it doesn't take long to change them and you get a chance to clean out the plug holes then. I use a setup with a wood dowel, rags, cleaners etc on a drill to get them spotless. Dirty plug holes take a toll on the boots and can cause misfires.
 

Machete

My Rig. 2000 EB 4x4 5.4L
Joined
Jul 18, 2012
Posts
843
Reaction score
348
Location
Illinois
Everybody here seems to be an expert, with an opinion... and we all know what opinions are like...
 

Thunderbirdsport

Full Access Members
Joined
Dec 10, 2020
Posts
377
Reaction score
233
Location
Missouri
Keep a set of plugs on hand. Just like oil, and filters....they WILL go bad and need replaced in time. Fact.
 
Top